根据短文理解完成下列各题。

C

    Shenzhen is a city in South China. It is not very big, but it has attracted people of the whole country and the whole world as well.

    Just about twenty years ago, it was only a small fishing village. There were not many people there. Most of them lived on fishing. Things have greatly changed since the 1980's. It became the first special economic zone (经济特区) in China.

    Because of the opening policy(政策), economic changes between China and the outside world have increased greatly. People can come and go easily between Shenzhen and Hong Kong. Both foreigners and Chinese have built a lot of factories, companies and tourists' attractions there. People all over the country have come to find jobs. Many of them have settled down in this new booming(兴起的) city.

    Shenzhen is developing so fast that it has become a well-known metropolis(大都市) in China.

  2015年春节前夕，我国的一个经贸代表团赴俄罗斯采购货物。读俄罗斯简图，结合俄罗斯环境特征，完成下题。

①核糖体  ②染色体  ③HIV病毒  ④中心体  ⑤钾离子载体．

用简便算法计算(-$\frac{1}{4}$+$\frac{1}{6}$-$\frac{1}{8}$+$\frac{1}{12}$)x(-24)

用简便算法计算(-$\frac{1}{4}$+$\frac{1}{6}$-$\frac{1}{8}$+$\frac{1}{12}$)x(-24)